OM642 belt rubber shavings
 

My 2008 ML320 has been shedding belt material. There is a slight oil leak from the intake, I’m dealing with it. Because of that, I had this black plastic intake silencer removed and fully cleaned about 500 miles ago. It had rubber shavings on it then. But it was fully cleaned, drove 500 miles, and:

https://i.imgur.com/X7j7s1Jl.jpeg

https://i.imgur.com/43a02djl.jpeg

The shavings are rubber. Belt doesn’t look bad, no chunks, cracks, etc.

This is what the shavings look like. Rubber fluff:

https://i.imgur.com/K0GCahfl.jpeg

It’s an 8 rib belt. All pullies seem fine, spin ok, etc. Engine is super smooth and everything works fine. No weird movement or oscillations on the belt.

I have records, but I don’t think I’ve seen records of the tensioner. Could it be that? Any other ideas?

Thanks!

Here's a good set of pics to do a visual on your tensioner.

https://sprinter-source.com/forums/index.php?threads/100371/

it's possible that as it wears it jutts out further and is causing the side of the belt to rub against something.

How many miles are on it? Replace all idler pulleys and tensioner pully assy and belt by no later than 200k miles.

Thanks, those are good tips!

199k, I need to look back in the records to see what has been swapped to date.

In the second picture posted the belt appears to be running over the edge of the pulley at top of photo.
I think that is the tensioner pulley , anyway the belt should be running straight over it so either there is a fault there or further back in the belt run.
Check the alternator clutch pulley isn’t winding itself off and moving the belt over.

This is sign it is time to replace the belt idler pulley(s) and tensioner pulley assembly in my opinion.

You are at mileage where it is time to replace these parts if they are original.

Thanks. I just realized I had a photo of the tensioner from April when I was cleaning it all up.

https://i.imgur.com/l8DjYuPl.jpeg

And I’m chasing the oil leak too.

https://i.imgur.com/kgSnCMzl.jpeg